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willaien

New Member
Joined
Feb 22, 2021
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6
Good afternoon, been looking at the Bluetti AC200P, but I also want to know how a home-built system would work and compare, and using the 640Wh "Milk Crate" build as a basis, I've been looking at a 24V system:

MPPT Controller: https://www.amazon.com/dp/B01MSYGZGI (40A Renogy)
Battery w/ BMS: https://www.amazon.com/dp/B08P6LP1J9 (24v 100Ah Ampere Time - I'm aware this is overpriced, just an example unit)
Inverter: https://www.amazon.com/dp/B07GDH711G (2000w 24v Giandel)
AC Charger: https://www.amazon.com/dp/B08GFQZFC1 (10a, Adjustable voltage, DOKO)

In addition, I'd have a buck converter set to 10A@13.8V for powering 12v DC things, and the same USB power output mentioned in the video, since it accepts 24v input. I'd also have 2 fuse blocks, one for 12v the other for 24v. The buck converter would be upgraded as needed for more 12v output.

What I want to know is if there's any glaring issues, i.e. is there anything that will prevent this system from working, and if these specs are true about the resulting build:
Inputs:
AC Input - 240W
PV Input - 1000W

Outputs:
AC 2000W, 2400W Peak (100A * 24V)
DC 10A@13.8v, whatever I fuse it at for 24V, up to 100A, Multiple USB ports per the spec of the USB charger

Storage:
2560Wh nominal, realistic usage in practice closer to 2300Wh

PV Inputs:
From what I understand, this system should be able to charge at roughly 1kW, however overpaneling it seems to be a bit tricky. Assuming I'm using this for the panel:
I believe that I can do a 5x4 configuration for a 2000W theoretical max, however the charging circuitry would only output 1000W to the batteries. Would 5 in series, paralleled 4 times be a valid configuration?

Misc:
There's no reason why I wouldn't be able to charge and run in this configuration, right? Does the choice of a battery with a built-in BMS limit my future expandability? How difficult would it be to add more of these batteries in **parallel** in future. Edit: meant parallel not series.
 
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How difficult would it be to add more of these batteries in series in future?
It should be specified by the manufacturer whether their batteries can be hooked in series.

And, in the future you decide to add more batteries in series, that will increase the voltage and
possibly obsolete your SCC and inverter.
 
It should be specified by the manufacturer whether their batteries can be hooked in series.

And, in the future you decide to add more batteries in series, that will increase the voltage and
possibly obsolete your SCC and inverter.

I meant to say in parallel so that I wouldn't have to increase the voltage, but knowing that they can be hooked up in series... Maybe I'd be better off with 2 of these:
https://www.amazon.com/dp/B088RM4W48 (12v, 200Ah, 100A BMS) from the get-go, then. It claims to support up to 4 in series. It'd be the same voltage as the build I have laid out, but only cost a little bit more in exchange for double the battery storage. Though I'd probably have to look at a beefier AC power supply, and I wouldn't always be able to do a full charge in a single day.
 
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So, I'd have to go in series rather than parallel.
If you want to stay at 24v, you'd have to stay in parallel.
Maybe I'd be better off with 2 of these:
>The battery can be connected in parallel and series for large capacity.

That would be a big battery. Off hand, your 40a SCC is looking smallish and the 10a charger looking REALLY small.

I'd say step back and do an energy audit to get a feel for how much energy you need and want. Then build the system around that rather than something abstract.
 
If you want to stay at 24v, you'd have to stay in parallel.

>The battery can be connected in parallel and series for large capacity.

That would be a big battery. Off hand, your 40a SCC is looking smallish and the 10a charger looking REALLY small.

I'd say step back and do an energy audit to get a feel for how much energy you need and want. Then build the system around that rather than something abstract.
Thanks for the feedback! Kill-a-watt on the way, not jumping on this too terribly soon.
 
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